dues?

Yes, most sororities have payment plans and I believe that some even have reduced/covered dues if you are financially eligible! You can ask these sort of questions on philanthropy day when chapters discuss their new member/house dues. Good luck :)

^^^ yes! PHA also has a scholarship once a month called Greek Geek and I think it's worth $300 or somewhere around there!

I wouldn't go into further debt just to be in a sorority. Do you really want to be paying 15 years down the road for something that is a luxury, not a necessity? Our generation is screwed when it comes to college debt. It is preventing us from traveling, buying a house or even having the freedom to get out of a bad job situation after we graduate. I have loved my sorority experience, but I didn't have to borrow to do it. If you know ahead of time that you won't be in a house, you can develop a strong bond with a group of girls in the dorm that also will last a lifetime. My brother is 7 years older than me and he and his wife wanted to buy a house that they fell in love with. They both have good jobs but they were turned down for a mortgage because their loans from grad school are too high. They were told they wouldn't qualify for a mortgage until they pay down those loans. They were devastated. It's just not worth it, IMO.

These are all good points. What about informal recruitment? Any advice/opinions on that?

Being in a sorority is very expensive. It depends on the chapter, but for every chapter you're going to be paying around 1500-200" a year just in dues and parlor fees. Then there's living in house, and Mizzou sororities are starting to require people to live in as pledge classes have been getting smaller but they still have to fill the house. It's a real financial burden and if you're struggling to pay dues each month it's going to put a burden on your experience.
To me, it seems illogical to get a loan to pay for your sorority. That's going to cause stress down the road when your college experience could be great without a sorority. If you are already worrying about finances, I think you should think long and hard about it, because it really sucks if you rush and end up dropping because you can't afford it. For you and for your sisters.
If you do informal recruitment, you'll still pay the same dues (though maybe one less semester if you wait till spring rush). So it wouldn't really make a big difference, other than saving the registration fee for recruitment.